feat: expose trivy.timeout to configure the duration to wait for scan completion

[zyyw]

Thank you for contributing to Harbor!

Comprehensive Summary of your change

Issue being fixed

Fixes #20219

Please indicate you've done the following:

• Well Written Title and Summary of the PR
• Label the PR as needed. "release-note/ignore-for-release, release-note/new-feature, release-note/update, release-note/enhancement, release-note/community, release-note/breaking-change, release-note/docs, release-note/infra, release-note/deprecation"
• Accepted the DCO. Commits without the DCO will delay acceptance.
• Made sure tests are passing and test coverage is added if needed.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed in website repository.

[zyyw]

one example of exposing config for trivy-adapter is here:

• https://github.com/goharbor/harbor/pull/19996/files

The env.jinja file and configs.py already have the code change for SCANNER_TRIVY_TIMEOUT.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 67.57%. Comparing base (b7b8847) to head (2b2e1a7).
Report is 127 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #20257      +/-   ##
==========================================
+ Coverage   67.56%   67.57%   +0.01%     
==========================================
  Files         991     1004      +13     
  Lines      109181   110578    +1397     
  Branches     2719     2781      +62     
==========================================
+ Hits        73768    74728     +960     
- Misses      31449    31825     +376     
- Partials     3964     4025      +61     

Flag	Coverage Δ
unittests	67.57% <ø> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

see 518 files with indirect coverage changes

[wy65701436]

lgtm

[MinerYang]

lgtm